QFEXT is the leading international conference held every two years, highlighting progress in quantum vacuum energy phenomena, the Casimir effect, and related topics, both experimentally and theoretically.This proceedings volume, featuring contributions from many of the key players in the field, serves as a definitive source of information on this subject, which is playing an increasingly important role in nanotechnology and in understanding fundamental issues in physics such as renormalization and in the search for new physics including fifth forces and dark energy.
This volume contains papers based on talks delivered at the Fourth Workshop on Quantum Field Theory Under the Influence of External Conditions. This series of workshops, held at the Institute for Theoretical Physics of the University of Leipzig, was launched in 1989. The present meeting took place 50 years after Hendrik B Casimir discovered the effect named after him. This effect was found by Casimir in investigating the retarded long range van der Waals forces in colloids and re-expressing them as a change in the vacuum energy of the electromagnetic field. The story of why this work was done was told by Casimir himself at the workshop. A historical account of the development of vacuum energy in quantum theory starting from Planck's half quanta was given by H Rechenberg. Another interesting topic was about a possible explanation of sonoluminescence as a dynamical Casimir effect. Kim Milton reported on the work done by Julian Schwinger on this topic during the last years of the great physicist's life, as well as on his own research. M Bordag (Leipzig) provided a general analysis of the ultraviolet divergences of the vacuum energy of a dielectric sphere.The Casimir effect had been experimentally verified 10 years after its discovery on a rather qualitative level. Only last year and in another experiment this year, it became also quantitatively well established. It turned out to be of unexpectedly high sensitivity with respect to the presence of the so-called fifth forces, as V Mostepanenko showed in his talk.Modern methods of computing the Casimir effect rely on zeta functional regularization and heat kernel expansion. This mathematical background, together with a broader embedding into expansions of various spectral quantities, was the subject of the talk by S Fulling. Recent progress in the computation of the heat kernel coefficients was reported by V Kornyak and K Kirsten.A number of talks were devoted to magnetic background fields of various types; for instance, new trends in the Aharonov-Bohm effect. In cosmology, negative energy densities and the role of adiabatic vacuum states in a de Sitter universe were discussed.
Julian Schwinger (1918-1994) was one of the giants of 20th Century science. He contributed to a broad range of topics in theoretical physics, ranging from classical electrodynamics to quantum mechanics, from nuclear physics through quantum electrodynamics to the general theory of quantum fields. Although his mathematical prowess was legendary, he was fundamentally a phenomenologist. He received many awards, including the first Einstein Prize in 1951, and the Nobel Prize in 1965, which he shared with Richard Feynman and Sin-itiro Tomonaga for the self-consistent formulation of quantum electrodynamics into a practical theory. His more than 70 doctoral students have played a decisive role in the development of science in the second half of this century.This important volume includes many of Schwinger's most important papers, on the above and other topics, such as the theory of angular momentum and the theory of many-body systems. The papers collected here continue to underlie much of the work done by theoretical physicists today.
The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
